Pneumatic cushion for keys



1.]. COOMBER.

PNEUMATIC CUSHION FOR KEYS.

APPLICATION FILED MAR. 14, 192!- 1 9 3 *m 57% Patented Nov. 22 1921 UNITED STATES PATENT OFFICE.

JAMES J. COOMBER, OF HOBOKEN, NEW JERSEY, ASSIGNOR TO MUNSON SUPPLY COMPANY, OF NEW YORK, N.'Y.,

A CORPORATION OF NEW YORK.

PNEUMATIC CUSHION FOR KEYS.

Specification of Letters Patent.

Patented ov. 22, 1921.

Application filed March 14, 1921. Serial No. 452,159.

To all tvhom it may coacern:

Be it known that I, JAMES J. COOMBER, a

' citizen of, the United States, and resident of Hoboken, in the State of New Jersey, have invented certain new and useful Improvements in Pneumatic Cushions for Keys, of which the following is a specification.

This invention relates to pneumatic cushions for keys, pertaining more particularly to cushion structures for typewriting keys.

Cushioning structures for this purpose have generally embodied a cushioning member of resilient material, such as rubber, and a securing member, generally metallic, the latter member being generally formed with a cavity to receive a portion of the cushioning member, the upper edge of the cavity walls having an annular inturned edge adapted to enter a properly-positioned a11- nular groove formed in the cushioning member, thus tending to retain the cushioning member in position on the securing member. The cushioning member, in some cases, is formed with an under cavityleaving an annular portion located below the edge of the securing memberthe presence of the under cavity permitting the desired give to the top of the cushion when the latter is struck in the typing operation.

While such structures have proved efiicient in service, the have certain disadvantages Which tent to affect the service conditions of the cushions. For instance, the presence of the groove so decreases the thickness of the walls of the cushion as to make the cushion structurally weak at this point, especially in use where the difference in resiliency between the outer edge of the top surface and the center tends to permit of relative movement such as tends to break down the weak connection at this point. In addition, the annular portion seated in the securing member cavity-located below this groovemay also be affected when assembling the two members, since the weak connectlon may not force this portionmore or less contracted to permit insertion into the cavity-to spread out properly after the edge has entered the groove, thereby preventing the desired location of this annular portion and tending to produce a formation which this weak connection tends to reduce the resilient action of the top of the cushion, since the part of the annular seated portion of the cushion which extends inwardly beyond the edge is so small as to offer little aid in the support of the top, so that the resistance against damage of the top is entirely dependent on the top itselfto increase the thickness of the annular portion would restrict the area of thecushion cavity and decrease the desired resiliency.

The present invention is designed to overcome these disadvantages by eliminating this source of weakness of the cushioning member, and in addition, by strengthening the annular portion through a reinforcing element, thus avoiding the conditions which inherently act to decrease the life of the cushioning member and meet the conditions of heavy service. Qther objects are to provide a construction which is simple and eflicient in operation, neat and attractive in appearance, durable in construction, and which can be manufactured at a relatively low cost.

To these and other ends, the nature of which will be readily understood as the invention is hereinafter disclosed, said invention consists in the improved construction and combination of parts, hereinafter fully described, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the accompanying drawings, in which similar reference characters indicate similar parts in each of the views,

Figure 1 is a view partly in elevation and partly in section showing one embodiment of the invention as applied to a typewriter Fig. 2 is a perspective view of the complete cushioning structure of Fig. 1.

Fig. 3 is a central vertical section of the cushioning member.

Fig. 4 is a horizontal sectional view taken on line 4--4 of Fig. 3.

In the present embodiment the securing member 10 is formed with two cavities, this being provided by a partition 10, between the upper and lower planes of the member. that portion of the member above the partition being of double thickness, the portion below the partition being of single thickness and being formed with an indentation 10 which acts to maintain the member in posi- "tion on the key 11. This general formation the particular form which the portion below the lip may take being a matter of design, the curved form, however, lending itself to an easier securing operation and being less damaging to the cushion member.

The cushioning member 12 is preferably of the general formation shown in Fig. 3, embodying the top or crown portion 12, the body or annular portion 12", and if desired, the web formation 12shown more particularly in Fig. 4,and shown as located in the general cavity of the-member and preferably of less depth than portion 12". The crown portion is of greater diameter than body portion 12', thus providing a simple shoulder effect, this shoulder, when the members are assembled, practically resting on the cap lip. Portion 12 is substantially of equal thickness crosssectionally throughout its vertical height, so that there is no weakened formation present below the crown-portion.

Portion 12 preferably carries a reinforcing element 13 of suitable type, this element being shown as an annular member, preferab y metallic, embedded within the portion, and with its upper edge spaced from and below the plane of the line of juncture of the crown and annular portions. The element is preferably provided with inwardly projecting or inturned portions 13 which tend to maintain the position of the element within the annular portion. Element 13 is preferably molded in the annular portion when the cushion is being manufactured.

'In assembling the two members, the annular portion of the cushion is slightly compressed to permit it to pass within the lip of the cap, where the lip is provided in advance of the assembly. Obviously, the

- cap may have the doubled portion uncurved and then bent inward to produce the lip effect after the cushion has been seated. In the assembly, however, the lip is located be tween the planes of the body portion and the upper edge of element 13 and therefore within the non-reinforced zone of the annular portion, so that compression of the latter can be readily had, as indicated in Fig; 1, the compression being effective between the crown portion and the reinforced zone of the annular portion, saidlatter zone not aemm only insuring thatthe normal configuration of the confined portion will be properly maintained, but offering a structural formation which tends to prevent ready withdrawal from its seating cavity. As aresult,

the cushion will remain properly seated even under extreme service conditions. And since the unreinforced zone is not weakened structurally there is little or no liability of the crown portion beingbroken from this annular portion, especially since the lip is of a configuration which offers no cutting action on .the cushion material. Furthermore, the pressure provided in striking the cushion is less liable to damage the formachanges made, being a construction easilymolded. The cap formation can be readily produced by a die operation, so that the completed construction can be manufactured at relatively low cost.

While I have herein shown and described a preferred form of construction, it will be readily understood that changes or'modifications therein may be found desirable or essential in meeting the various exigencies of use, and I desire to be understood as reserving the right to make any and all such changes or modifications as may be found desirable or essential, in so faras the same may fall within the spirit and scope of the invention as expressed in the accompanying claims when broadly construed.

Having thus described my invention, what I claim as new is 1. As a new article of manufacture, a pneumatic cushion for keys comprising a resilient cushioning member adapted for attachment to a' securing member, the said cushioning member including a top or crown portion and a depending body portion, the said depending portion being provided with a rigid reinforce in the body thereof adapted for cooperation with the said securing member.

2. A pneumatic cushion for keys comprising a resilient cushioning member, and a securing member, said securing member having a cavity to receive the cushioning member and a lip to maintain the cushioning member in seated position, said cushionmg member havlng a rigid remforce tending to maintain the seated condition of the and a-Iip to maintain the cushion member in below the seated position, said cushionmember having a rigid reinforce below the plane of the lip tending to maintain the seated condition of the cushion member.

4. A pneumatic cushion for keys comprising a resilient cushion member, and .a securing member, said securing member having a cavity to receive the cushion member and a lip to maintain the cushion member in seated position, said cushion member havin an integral annular portion extending Within the cavity and adapted to contact with cavity walls, said portion -carrying a rigid reinforce.

5. A pneumatic cushion for keys comprising a resilient cushion member, and a securing member, said securing member havng a cavity to receive the cushion member and a lip to maintain the cushion member in seated position, said cushion member having an integral annular portion extending within the cavity and adaptedto contact with cavity walls, said portion having an annular metallic element embedded therein to constitute a reinforce therefor.

6'. A pneumatic cushion for keys comprising a resilient cushion member, and a securing member, said securing member .hav-

mg a cavity to receive the cushion member and a lip to maintainthe cushion member in seated position, said cushion member having an integral annular ortion extending within the cavity and a apted to contact with cavity walls, said portion having an annular metallic element embedded therein 1plane of said lip to constitute a reinforce t erefor.

7. A pneumatic cushion for keys comprising a resilient cushion member, and a securlng member, said securing member having a cavity to receive the and a lip to maintain the cushion member in seated position, said cushionmember having an. integral annular portion extending within the cavity and adapted to contact with cavity walls, said portion having an cushion member L annular metallic element'embedded therein to constitute a reinforce therefor, said element having at least one laterally-pro ectm'g portion for maintaining the position of the element. p

8. A pneumatic cushion for keys comprising a resilient cushion member, and asecuring member, said securing member having a cavity to receive the cushion member and a lip to maintain the cushion member in seated position, said cushion member having an integral annular rtion extending within the cavity and a apted to contact with cavity walls, said portion having an annular metallic element embedded therein to constitute a reinforce therefor, said element having at least onelaterally-project mg portion at its upper edge for maintaining the position of the element.

9. A pneumatic cushion for keys comprising a resilient cushion member, ing member, said securing member having a pair of cavities separated by a partition intersecting the member axis intermediate the opposite ends of the member, the walls of one of said cavities being of double thickness with the marginal edge shaped to form an annular lip of a/diameter smaller than the diameter of the said walls, said cushion member being seated in said cavity and maintained in position by the lip.

10. As a new article of manufacture, a

pneumatic cushion for keys comprising a resilient cushioning member adapted for atand a securtachment to a securing member, the said cushioning I crown portion and a depending annular body portion of a diameter less than the crown portion, the said de ndlng portion being provided with a rigid annular reinforce in the body'thereof adapted for cooperation with the said securing member.

Signed at Hoboken, in the county of Hudson and State of New Jersey this 5th day of March, A. D. 1921.

JAMES J. COOMBER.

member including atop or 

